The present invention relates to a tubular prosthesis and, more particularly, to a radially expandable tubular prosthesis which allows controlled expansion in a circumferential direction following implantation while limiting expansion in a longitudinal direction.
The typical prosthesis of the prior art is manufactured with a predetermined diameter, that is, prostheses are manufactured in various sizes so that the physician may choose the most appropriate-sized prosthesis to replace or repair the damaged lumen in the patient. As far as length is concerned, the physician merely cuts the chosen prosthesis to size, the prosthesis typically being oversized in the longitudinal direction.
The commonly-employed prosthesis mentioned above is suitable for use in many situations. However, several applications may demand that the prosthesis be expandable in the radial direction. For example, one such application involves intraluminal implant procedures in which the prosthesis is delivered to a damaged lumen via a catheter. The technique requires that the implant be stored within the catheter (e.g., it may be rolled or bunched) prior to insertion of the catheter into the patient. Upon advancement of the catheter to the site of the damage, the implant is expelled from the catheter, unrolled (or unfolded) and thereafter secured to the lumen. Because of the procedure, it is difficult, if not impossible, for the physician to correct any mismatch in sizing that may occur between the implant and the host lumen. For example, if the physician miscalculates the size of the lumen receiving the implant or should the lumen prove to be larger or smaller than anticipated by the physician, the physician may not be able to securely fix the implant to the host lumen.
Another application in which it would be desirable to employ an expandable prosthesis involves the area of pediatrics. A common disadvantage encountered in conventional pediatric prostheses is the inability of the device to accommodate growth changes in the surrounding tissue as the child ages. Consequently, it is often necessary to perform several surgical procedures on a child to implant ever increasingly circumferentially-larger prostheses. It has traditionally been necessary to entirely remove and replace the implanted prosthesis with a larger-sized prosthesis as the child grows. Such a series of surgeries is traumatic to the body and has a degree of risk inherently associated therewith.
Accordingly, it would be desirable to provide a tubular prosthesis which allows for circumferential expansion such that the prosthesis could be readily deployed via a catheter for intraluminal delivery and, further, such that the prosthesis could be circumferentially expanded in vivo as the child grows, thereby eliminating the need, or at least the frequency, for surgical replacement of the implant.